<?php
/**
 * PHPExcel
 *
 * Copyright (c) 2006 - 2013 PHPExcel
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * @category   PHPExcel
 * @package    PHPExcel_CachedObjectStorage
 * @copyright  Copyright (c) 2006 - 2013 PHPExcel (http://www.codeplex.com/PHPExcel)
 * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt	LGPL
 * @version    1.7.9, 2013-06-02
 */


/**
 * PHPExcel_CachedObjectStorage_CacheBase
 *
 * @category   PHPExcel
 * @package    PHPExcel_CachedObjectStorage
 * @copyright  Copyright (c) 2006 - 2013 PHPExcel (http://www.codeplex.com/PHPExcel)
 */
abstract class PHPExcel_CachedObjectStorage_CacheBase {

	/**
	 * Parent worksheet
	 *
	 * @var PHPExcel_Worksheet
	 */
	protected $_parent;

	/**
	 * The currently active Cell
	 *
	 * @var PHPExcel_Cell
	 */
	protected $_currentObject = null;

	/**
	 * Coordinate address of the currently active Cell
	 *
	 * @var string
	 */
	protected $_currentObjectID = null;


	/**
	 * Flag indicating whether the currently active Cell requires saving
	 *
	 * @var boolean
	 */
	protected $_currentCellIsDirty = true;

	/**
	 * An array of cells or cell pointers for the worksheet cells held in this cache,
	 *        and indexed by their coordinate address within the worksheet
	 *
	 * @var array of mixed
	 */
	protected $_cellCache = array();


	/**
	 * Initialise this new cell collection
	 *
	 * @param    PHPExcel_Worksheet $parent The worksheet for this cell collection
	 */
	public function __construct(PHPExcel_Worksheet $parent) {
		//	Set our parent worksheet.
		//	This is maintained within the cache controller to facilitate re-attaching it to PHPExcel_Cell objects when
		//		they are woken from a serialized state
		$this->_parent = $parent;
	} //	function __construct()


	/**
	 * Return the parent worksheet for this cell collection
	 *
	 * @return    PHPExcel_Worksheet
	 */
	public function getParent() {
		return $this->_parent;
	}

	/**
	 * Is a value set in the current PHPExcel_CachedObjectStorage_ICache for an indexed cell?
	 *
	 * @param    string $pCoord Coordinate address of the cell to check
	 *
	 * @return    boolean
	 */
	public function isDataSet($pCoord) {
		if ($pCoord === $this->_currentObjectID)
		{
			return true;
		}

		//	Check if the requested entry exists in the cache
		return isset($this->_cellCache[$pCoord]);
	} //	function isDataSet()


	/**
	 * Move a cell object from one address to another
	 *
	 * @param    string $fromAddress Current address of the cell to move
	 * @param    string $toAddress   Destination address of the cell to move
	 *
	 * @return    boolean
	 */
	public function moveCell($fromAddress, $toAddress) {
		if ($fromAddress === $this->_currentObjectID)
		{
			$this->_currentObjectID = $toAddress;
		}
		$this->_currentCellIsDirty = true;
		if (isset($this->_cellCache[$fromAddress]))
		{
			$this->_cellCache[$toAddress] = & $this->_cellCache[$fromAddress];
			unset($this->_cellCache[$fromAddress]);
		}

		return true;
	} //	function moveCell()


	/**
	 * Add or Update a cell in cache
	 *
	 * @param    PHPExcel_Cell $cell Cell to update
	 *
	 * @return    void
	 * @throws    PHPExcel_Exception
	 */
	public function updateCacheData(PHPExcel_Cell $cell) {
		return $this->addCacheData($cell->getCoordinate(), $cell);
	} //	function updateCacheData()


	/**
	 * Delete a cell in cache identified by coordinate address
	 *
	 * @param    string $pCoord Coordinate address of the cell to delete
	 *
	 * @throws    PHPExcel_Exception
	 */
	public function deleteCacheData($pCoord) {
		if ($pCoord === $this->_currentObjectID)
		{
			$this->_currentObject->detach();
			$this->_currentObjectID = $this->_currentObject = null;
		}

		if (is_object($this->_cellCache[$pCoord]))
		{
			$this->_cellCache[$pCoord]->detach();
			unset($this->_cellCache[$pCoord]);
		}
		$this->_currentCellIsDirty = false;
	} //	function deleteCacheData()


	/**
	 * Get a list of all cell addresses currently held in cache
	 *
	 * @return    array of string
	 */
	public function getCellList() {
		return array_keys($this->_cellCache);
	} //	function getCellList()


	/**
	 * Sort the list of all cell addresses currently held in cache by row and column
	 *
	 * @return    void
	 */
	public function getSortedCellList() {
		$sortKeys = array();
		foreach ($this->getCellList() as $coord)
		{
			sscanf($coord, '%[A-Z]%d', $column, $row);
			$sortKeys[sprintf('%09d%3s', $row, $column)] = $coord;
		}
		ksort($sortKeys);

		return array_values($sortKeys);
	} //	function sortCellList()


	/**
	 * Get highest worksheet column and highest row that have cell records
	 *
	 * @return array Highest column name and highest row number
	 */
	public function getHighestRowAndColumn() {
		// Lookup highest column and highest row
		$col = array('A' => '1A');
		$row = array(1);
		foreach ($this->getCellList() as $coord)
		{
			sscanf($coord, '%[A-Z]%d', $c, $r);
			$row[$r] = $r;
			$col[$c] = strlen($c) . $c;
		}
		if (!empty($row))
		{
			// Determine highest column and row
			$highestRow = max($row);
			$highestColumn = substr(max($col), 1);
		}

		return array(
				'row' => $highestRow,
				'column' => $highestColumn
		);
	}


	/**
	 * Return the cell address of the currently active cell object
	 *
	 * @return    string
	 */
	public function getCurrentAddress() {
		return $this->_currentObjectID;
	}

	/**
	 * Return the column address of the currently active cell object
	 *
	 * @return    string
	 */
	public function getCurrentColumn() {
		sscanf($this->_currentObjectID, '%[A-Z]%d', $column, $row);

		return $column;
	}

	/**
	 * Return the row address of the currently active cell object
	 *
	 * @return    string
	 */
	public function getCurrentRow() {
		sscanf($this->_currentObjectID, '%[A-Z]%d', $column, $row);

		return $row;
	}

	/**
	 * Get highest worksheet column
	 *
	 * @return string Highest column name
	 */
	public function getHighestColumn() {
		$colRow = $this->getHighestRowAndColumn();

		return $colRow['column'];
	}

	/**
	 * Get highest worksheet row
	 *
	 * @return int Highest row number
	 */
	public function getHighestRow() {
		$colRow = $this->getHighestRowAndColumn();

		return $colRow['row'];
	}


	/**
	 * Generate a unique ID for cache referencing
	 *
	 * @return string Unique Reference
	 */
	protected function _getUniqueID() {
		if (function_exists('posix_getpid'))
		{
			$baseUnique = posix_getpid();
		}
		else
		{
			$baseUnique = mt_rand();
		}

		return uniqid($baseUnique, true);
	}

	/**
	 * Clone the cell collection
	 *
	 * @param    PHPExcel_Worksheet $parent The new worksheet
	 *
	 * @return    void
	 */
	public function copyCellCollection(PHPExcel_Worksheet $parent) {
		$this->_currentCellIsDirty;
		$this->_storeData();

		$this->_parent = $parent;
		if (($this->_currentObject !== null) && (is_object($this->_currentObject)))
		{
			$this->_currentObject->attach($this);
		}
	} //	function copyCellCollection()


	/**
	 * Identify whether the caching method is currently available
	 * Some methods are dependent on the availability of certain extensions being enabled in the PHP build
	 *
	 * @return    boolean
	 */
	public static function cacheMethodIsAvailable() {
		return true;
	}

}
